During the 44th Session of the Sub-Committee of Experts on the Globally Harmonized System of Classification and Labelling of Chemicals, Austria, the EU, Finland, Germany and the UK proposed revising Chapter 4.2 by adding the new hazard category related to global warming listed in the annexes to the Montreal Protocol. If the proposal is approved, the new classifications would be Hazardous to the Atmospheric System, which encompass both: Hazardous to the ozone layer; and Hazardous by contributing to global warming.

On July 27, 2023, the United Nations Economic Commission for Europe (UNECE) published the Globally Harmonized System of Classification and Labelling of Chemicals (GHS Rev.10). Revisions have been made to several parts, including: the classification procedure; the use of non-animal testing methods; precautionary statements; and annexes 9 and 10.

UN GHS refers to the Globally Harmonized System of Classification and Labelling of Chemicals (purple book). It is an international system created by United Nations Committee of Experts on GHS, International Labor Organization (ILO) and the Organization for Economic Co-operation and Development (OECD) to address the classification of chemicals by types of hazards and harmonize hazard communication elements, including labels and safety data sheets. It aims at providing a basis